There should be another option on the installer page that you reference to 'Create Custom Layout.' It is the last option offered. From there, you can select your / install partition and choose which, if any, other partitions you want to incorporate and their respective mount points.

If it does not appear, you might try rebooting with a current GParted Live Disk and reformat your chosen partition to ext4. It's a great tool to have in your collection and I always recommend using this method for manipulating partition tables, instead of relying on the distro's installer version.

New CoreCD (SpinBase) has no longer the possibility to manually configure your partitions layout due to the limitations of Fedora Anaconda installer.If you want to install it, erase sda5 and then use "Use free space option". Otherwise, use CoreCDX with graphical installation.